Nuprl Lemma : integer-sqrt-ext
∀x:ℕ. (∃r:ℕ [(((r * r) ≤ x) ∧ x < (r + 1) * (r + 1))])
Proof
Definitions occuring in Statement : 
nat: ℕ, 
less_than: a < b, 
le: A ≤ B, 
all: ∀x:A. B[x], 
sq_exists: ∃x:A [B[x]], 
and: P ∧ Q, 
multiply: n * m, 
add: n + m, 
natural_number: $n
Definitions unfolded in proof : 
member: t ∈ T, 
exp: i^n, 
primrec: primrec(n;b;c), 
subtract: n - m, 
fastexp: i^n, 
efficient-exp-ext, 
so_apply: x[s1;s2], 
natrec: natrec, 
genrec: genrec, 
genrec-ap: genrec-ap, 
integer-sqrt, 
integer-nth-root, 
div_nat_induction, 
rem_bounds_1, 
decidable__lt, 
decidable__equal_int, 
decidable__squash, 
decidable__and, 
decidable__less_than', 
decidable__int_equal, 
decidable_functionality, 
squash_elim, 
sq_stable_from_decidable, 
any: any x, 
iff_preserves_decidability, 
sq_stable__from_stable, 
stable__from_decidable, 
uall: ∀[x:A]. B[x], 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]), 
so_apply: x[s1;s2;s3;s4], 
so_lambda: λ2x.t[x], 
top: Top, 
so_apply: x[s], 
uimplies: b supposing a, 
implies: P ⇒ Q, 
has-value: (a)↓, 
prop: ℙ
Lemmas referenced : 
integer-sqrt, 
lifting-strict-int_eq, 
strict4-decide, 
lifting-strict-decide, 
lifting-strict-less, 
cbv_sqequal, 
has-value_wf_base, 
efficient-exp-ext, 
integer-nth-root, 
div_nat_induction, 
rem_bounds_1, 
decidable__lt, 
decidable__equal_int, 
decidable__squash, 
decidable__and, 
decidable__less_than', 
decidable__int_equal, 
decidable_functionality, 
squash_elim, 
sq_stable_from_decidable, 
iff_preserves_decidability, 
sq_stable__from_stable, 
stable__from_decidable
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
equalityTransitivity, 
equalitySymmetry, 
isectElimination, 
baseClosed, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_isectElimination, 
baseApply, 
closedConclusion, 
hypothesisEquality, 
lambdaFormation, 
callbyvalueReduce
Latex:
\mforall{}x:\mBbbN{}.  (\mexists{}r:\mBbbN{}  [(((r  *  r)  \mleq{}  x)  \mwedge{}  x  <  (r  +  1)  *  (r  +  1))])
Date html generated:
2018_05_21-PM-07_52_25
Last ObjectModification:
2018_05_19-PM-04_50_03
Theory : general
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